The argument for war in Henry V

The Archbishop of Canterbury advises Henry he is rightful king of France under feudal law.

Then he and other clerics and nobles urge war, not because it would serve the interests of the English people, nation, or state, much less the French people, nation, or state, but because it would serve the glory and thirst for power and wealth of the King and his own feudal vassals.

And vindicate feudal law, thus affirming the unquestioned legitimacy of same.

Which is far from denying national feeling enters the matter.

Perhaps anachronistically.

That is for the ordinary soldiery who have really nothing to gain and can only lose by participating in this war.

Dulce et decorum est pro patria mori is for them.